Small, single burner portable stoves ("cookers") using butane or butane/propane mixtures have become increasingly widely used. Such cookers use a standard disposable thinwalled "aerosol type" canister containing approximately 8 ounces of liquified fuel at a pressure that varies with ambient temperature. The canister is equipped with a springloaded pinvalve which, when depressed, permits gaseous fuel to be ejected. An orienting slot in the canister body cooperates with an aligning member on the pressure regulator to ensure that an internal canister standpipe is nominally vertical when the appliance is in use, thereby permitting only gaseous, not liquid, fuel to be ejected.
The gas canister in such a portable cooker is generally contained in an accessible, ventilated, lidded compartment within the cooker, approximately 4 inches from the burner itself. After being placed in position, the fuel canister is forcibly inserted into the pressure regulator inlet by means of a user-operated lever and associated linkage.
These cookers are typically inexpensively constructed and intended for portable use. Their general design and construction renders them extremely susceptible to misuse and abuse. Gas leakages and resulting flames frequently occur at the pressure regulator or at the canister-regulator interface.
Within the last several years, such cookers have increasingly begun to appear aboard pleasure boats, particularly aboard small powerboats wherein permanently built-in cooking appliances are often not provided. Because a small boat includes many closed spaces, such as bilges and the engine compartment, and because butane/propane mixtures are heavier than air, there is a concern that fuel leaking from the stove, fuel canister or both, will be ignited by one of the many potential ignition sources commonly found aboard such craft. The greatest hazard, however, is the abuse-to-failure of the thinwalled fuel canister itself while it is in actual use within the cooker. Such abuse is encouraged by the design of these portable cookers, such that it is very easy for an unwary user to create conditions in which the canister can and will rupture, often with serious consequences.
At the same time, it is to be noted that one type of cooking appliance, using compressed or liquified gas, has been used aboard thousands of pleasure boats for decades and has compiled an admirable safety record. In these appliances, the fuel canister is not housed within the appliance itself. Rather, the fuel canister, or canisters, is typically contained within a remotely located dedicated compartment which opens only to the outside deck, is isolated by gastight seals from all of the interior spaces of the boat, and is vented overboard so that accidental gas leakages are harmlessly discharged into open air. A supply pipe connects to the cooking appliance via a valve, inside the housing, which is controlled by a switch located near the appliance. The user thereby controls the fuel supply, shutting it off after use. Unfortunately, these installations are large, heavy, costly and thus are limited to use in larger craft.